Method of protecting conduits for electric conductors.



G. A. LUTZ.

METHOD OF PROTECTING CONDUITS FOR ELECTRIC CONDUCTORS,

APPLICATION FILED JAN.19,190J.

1,072,478. Patentd Sept; 9, 1913.

UNITED STATES PATENT OFFICE.

GEORGE A. LUTZ, OF PLAINFIELD, NEW JERSEY, ASSIGNOR T0 AMERICAN CIRCULAR LOOM COMPANY, OF PORTLAND, MAINE, A CORPORATION OF MAINE.

METHOD OF PROTECTING CONDUITS FOR ELECTRIC CONDUCTORS.

Specification of Letters Patent.

Application filed January 19, 1909.

Patented Sept. 9, 1913. Serial No. 473,157.

To all whom it may concern:

Be it known that I, Gnonon A. LU'IZ, a

. Protecting Conduits for Electric Conductors,

of which the following is a specification.

Metal conduits, such as pipes and tubes for electric conductors, outlet boxes, and other fittings used in systems of electrical distribution are liable to become oxidized or rusted in use, and to prevent such rusting and maintain the conductivity of the surface of such pipes and appliances it has been customaryto coat the outside or inside surfaces, or both, with a deposit of metal, such as an electrodeposit of zinc. But such coating or deposit does not always cover fully the entire surface of the metal article as spots or places are left unprotected, at which spots the oxidation or rusting can take place. This is due, so far as I am aware, to the fact that the electrodeposit of metal is not sufficiently homogeneous throughout, in that the metal during the process of being deposited becomes more or less rough or pitted, leaving small openings through the deposit.

The object of my invention is to cause the electrodeposit upon the surface of metal, such as galvanizing by the deposit of zinc on the metal, to thoroughly cover the surface of the metal upon which the deposit is placed, to prevent oxidation or rusting thereof.

In carrying out my invention I first thoroughly clean the surface of the metal to be coated, as by pickling, scouring or in any other well known manner, then apply a metallic deposit or coating thereon, preferably by the electroplating process, as by depositing zinc upon such surface, and I then apply pressure to such coating, as by drawing the coated metal article through a die, or by applying such pressure by means of revolving rolls, in contact with such coating or deposit, and if the interior surface of such article is coated with the metal I create pressure thereon by means of a suitable tool, such as a ball or an expanding burnishing tool, either drawn through the article or the article being drawn over the same. I11 the case of a the die.

pipe, where its interior and exterior surfaces are coated with the metal deposit, the pressure may be applied to the exterior and interior coatings simultmieously by drawing the coated pipe through a die while the bur nishing or rubbing tool is, within the pipe, acting on the coating, So that the one passage of the pipe along the die and tool would be sufficient to simultaneously rub or burnish both the exterior and interior coatings of the pipe. or rubbing of the metal deposits upon the pipe may be accomplished simultaneously with rotating rolls in contact with the exterior deposit and the ball or similar tool operating upon the deposit upon the interior of the pipe. Such rubbing and burnishing of the metal deposit or coating upon the article causes the metal'coating to flow, so that it will be thoroughly smoothed, and will fill spots or places left in the coating while being deposited, thereby causing the coatingto be continuous throughout. Such covering of the open spots or places in the electrodeposit upon the metal article protects the same, preventing oxidation or rusting thercat, and producing a more uniform and smooth protecting metallic coating upon and Within the metal article.

The accompanying drawing is a partial sectional View, illustrating an electroplated pipe in connection with an external die and interior ball adapted for rubbing and burnishing the metal deposits.

The die A may be of any suitable form, and may be similar to dies used in drawing metal, being shown supported in any suitable support B, the metal coating 0 upon pipe C being adapted to be drawn and burnishcd by the A as the pipe is pulled through The coating (2 upon the inner surface of pipe C is adaptedto be drawn and 'l'iurnislied by the tool or ball D within the pipe in contact with the deposit (2 The tool I) is shown attached to a rod E which may be held in any suitable manner. The arrangement is such that by having the tool 1) within die A. as shown. the pressure will be uniform. so that when the coated pipe C is pulled through the die both coatings 0 anr will be operated upon simultaneously.

It is obvious that if the pipe has the ex- The interior and exterior burnishing terior coating only the tool'D may be dispensed with,'and if the pipe has the interior coating only the die A may be dispensed with. The tool D also may be used on the interior of the pipe While. rotating rolls in place of the die A are used upon the exterior coating 0 ofthepipe. v While I have illustrated my improvements in connection Wit-h a pipe, it will be understood thatoutlet'boxes, and other fittings for systems of electrical distribution, having an :electrodeposit of metal upon the surface or surfaces, may be treated in the manner set forth by any suitable rubbing or burnishing tool. a I 1 I have described'iny invention in connection with pipe and appliances for systems of electrical distribution, butiit will be understood 1 that thearticles treated, are not confined to such use,as articles for other uses may be produced 'inaccordance with my invention,

Signed at New York city, in thecounty' of New York, and State of; New York, this 13th day of January, A. D1909.

' GEOR ,E A. LUTZ.

Witnesses: r

RA PH H. RAPHAEL,

, T. F. BOURNE.

fill open spots left-in. said 

